SRFirewall is an easy to use, but still quite capable firewall for Netfilter/iptables. It is a complete rewrite of Firewall/SOSDG, designed to make it easy for users to configure and protect their Linux servers, routers, and gateways.

MasarLabs PatD is a daemon to ping or traceroute remote hosts, using IPv4 or IPv6 ICMP packets. It runs without root privileges, listening on a TCP local port for hosts to check. It uses a protocol simple to implement, so is useful in situations in which you cannot send native ICMP packets (for example, from a Java program). pat is a client you can use to talk to patd.

Andrisoft WANSIGHT is a fully featured network traffic analyzer and collector. It provides in-depth traffic analysis, traffic accounting, and bandwidth monitoring, and enables you to generate complex traffic reports, graphs, and tops, instantly pin down the cause of network incidents, understand patterns in application performance, and make the right capacity planning decisions. It supports 10GbE packet sniffing and NetFlow, sFlow, and IPFIX.

dhcpy6d delivers IPv6 addresses for DHCPv6 clients, which can be identified by DUID, hostname, or MAC address, as in the good old IPv4 days. Addresses may be generated randomly, by range, or by arbitrary ID or MAC address. Clients can get more than one address, leases and client configuration can be stored in databases, and DNS can be updated dynamically.

force_bind allows you to force binding on a specific IP and/or port. It works with both IPv4 and IPv6. It is useful if you have a binary application without sources and without the ability to configure an address or port to bind to.

ip2clue provides access to multiple databases (Maxmind, Software 77, Webhosting.info and ip2location) to retrieve country information associated with IP addresses. It has a daemon that supports lots of concurrent connections and a client binary. Some client examples are also provided in languages including PHP and C.

radns is a small, portable client-side implementation of the RDNSS option in IPv6 Router Advertisements (RFC 5006) that is used to get the address of a resolving DNS server. It listens for Router Advertisements with the Recursive DNS Server (RDNSS) option and stores the addresses in a file following the same syntax as resolv.conf. It optionally calls a script to handle, for instance, DHCP clients that compete for ownership of /etc/resolv.conf or to set the DNS server on systems that don't use resolv.conf at all. It can be easily integrated with the resolvconf(8) program.

Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.